Combined switch and fuse cabinet



Jan- 13, 1931 B. D. HoRToN 1,788,719

COMBINED SWITCH AND FUSE CABINET Filed Deo. 8, 1922 5 Sheets-Sheet l gliZ-"l' www Erwan Hor Zon.

59% vri/1,6%

Jan. 13, 1931. v B D, HORTON 1,788,719

'COMBINED SWITCH AND FUSE CABINET Filed Dec. 8, 1922 5 Sheets-Sheet 2Jan. 1.3, 1931. I B. D. HORTON f 1,788,719

COMBINED SWITCH AND FUSE CABINET Filed Dep. 8, 1922 5 Sheets-Sheet 3 .f/Qg l I l I I I 3 I I I E 'ff J5 I E i I I i I I I r A"1 i I I 3 i 5 Il3 I:l:' I I 70---Ir` l ""I Jan. 13, 1931. B. D. HoRToN COMBINED SWITCHAND FUSE CABINET 5 sheets-shea 4 Filed Deo. 8, 1922 Zdnarss/ @mgm Jan.13, 1931. B. D. HoRToN COMBINED SWITCH AND FU-SE CABINET Filed Dec. v8,1922 5 Sheets-Sheet 5 NSK Patented Jan. 13, 1931 UNITED sfrATEs PATENTOFFICE BRYSON D. HORTON, OF DETROIT, MICHIGAN, ASSIGNOR TO SQUARE DCOMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN COMBINED SWITCHAND FUSE CABINET Application led December 8, 1922. Serial No. 605,637.

. My invention relates to switches and more particularly to that type,commonly known as protected lor armor-clad wherein the switch elementsand adjoining live parts of the circuit are housed. While I shalldescribe my invention as being particularly useful in connection withthis type of switch, I do not intend to limit myself yto this use solelyas it is apparent that my invention may have a wide lield of utility andadaptability wherever movable door cabinets are desirable, whether in'this art or in remote and nonanalogous arts.

It is commonly known that the demand for iron clad switches hasincreased in recent years, chiefly due to the rapidly increasingutilization of electrical power for industrial purposes. Armor-cladswitches have been adopted mainly because they reduce the element oflife hazard by completely housing the live and unprotected parts of theswitch and of the circuit where the switch is inserted. In order torender this type of switch elective and to guard against unauthorizedtampering therewith, an interlock is provided between the cover andswitch, so that the cover can not be opened while the switch is closed,and the switch closed while the cover is open. Such`a construction isundesirable in many cases, especially in industrial plants whereproduction can not be advantageously shut down in order to permitinspection of the switch atfrequent intervals. Accordingly, I havedisclosed in United States Letters Patent,

1,412,242, issued on April 11, 1922, an interlock mechanism capa le ofbeing disabled by a duly authorized erson, appointed to inspect theswitch, so t at it is no longer 1mperative to discontinue service to thecustomer during inspection of the-switch. Incidentally, anotherdifficulty arose in electrical transmission. It is well known that fusesshould never be removed from the circuit unless the switch is opened tobreak the circuit, as a quick break at the fuse terminals is notprovided for, and consequently the resultant arcing will burn theterminals. Another disadvantage lies in the fact that the fuses are aptto be removed at a time when current in the load line is imperative.

It is, therefore, an object of my invention to overcome thesediliculties by providing in connection with the switch box coverinterlock and disabling mechanism, means whereby the fuses are protectedagainst unauthor- 1zed tampering, but so related with the interlock,that displacement of the fuses is prevented while the switch is inclosed position.

It is a further object of my invention to provide a switch box having aswitch and a fuse compartment with separated doors for each compartment,so that access to one com- -at no time while the switch is closed maythe fuse displacement door be opened.

My invention further provides for permitting inspection of the fuseswhile the switch is closed. An inspection door, exposing to V1ew alimited area of the fuse compartment, is provided and so related withthe switch door that whenever the switch door is opened, the fuseinspection door may be also opened.

According to the teachings of this invention, the interlock isconstructed to prohibit the opening of the fuse displacement door whilethe circuit 'is closed, and therefore, removal of the fuses is renderedimpossible when the switch is closed. The disabling means abovedescribed may be termed a switch and fuse inspection door disablingmeans, as distinguished from a second disabler which I provide as one ofthe objects of my invention, to render the locking of the switch in openposition, by the interlock, in-

eiective, while the switch and fuse inspection doors are opened.

So far as I am aware, no attempt has heretoiore been made to provide forthe inspection of the fuses and at the same time prohibit theirdisplacement. Nor has there been an attempt to permit inspection of theswitch and fuses while the switch is closed.

Accordingly, I believe that am the iirst to provide such a construction,and shall therefore claim the same broadly.

My invention in its broadest aspect involves the provision of a cabinethaving doors thereon, and an interlock therefor, to permit opening ofthev doors only when certain conditions have been fulfilled within thecabinet. t is not necessary that the interlock cooperate only with thedoors of the cabinet, as interlocking of some other part of the cabinetmay be desired, this being however, a substitute for a door and includedwithin the scope of this invention.

A further object of my invention is the provision of a simple, compactand unitary interlock.

Another object is to construct this interlock so that it cooperates withthe doors, only when they are in closed position.

Another object is to arrange the switch lock disabler so that wheneiective, the fuse displacement door may not be opened, although theswitch may be open.

Another object is to have the inspection doors and fuse displacementdoor cooperate independently with the interlock when they` are closed.

Another object is to accomplish the above by the provision of lock barspreferably parallel to the door openings, and to each other.

Another object is to associate said lock bars with the interlock so thateach is independent in operation from the other.

ln order to apprise those skilled in the art how to construct andpractice my invention, I shall describe an embodiment thereof inconnection with the accompanying drawings which form part of thespecification.

In the drawings:

Figure 1 is a perspective view of a cabinet embodying my invention, withall the doors in closed position; v

Fig. 2 is a similar view, illustrating the switch and fuse displacementdoors in open position with the switch open;

Fig. 3 is also a similar view, but illustrating the switch closed "withthe switch and fuse inspection doors released by means of a disablingkey inserted at one side of the f cabinet;

Fig. 4 is a perspective view of the cabinet, showing the switch and fuseinspection doors released and a second disabling device in the same sideof the cabinet for permitting the switch tobe released and closed whilethese doors are open.

Fig. 5 is a vertical sectional view through theY cabinet, looking in thedirection of an interlock enclosed within a protective houslng S Fig. 6is a detail view of the interlock in position when the switch and allthe doors are closed;

Fig. 7 is a similar view or the interlock, butv illustrating it in aposition when the switch is open and the doors are closed;

Fig. 8 is a similar view showing the interlock in position when theswitch and all the doors are open; l

Fig. 9 is a similar view, illustrating the interlock in position whenthe switch is closed and the interlock is disabled to release the switchand fuse inspection doors;

Fig. 10 is a detail view oiE the same mechanism after the switchinterlock has been rendered ineffective and the switch closed during thetime the switch and fuse inspection doors are open;

Fig. 11 is a detail view taken on line ll-li looking in the direction ofthe arrows in Fig. 6;

Fig. 12 is a detail view taken on line 12-12 in Fig. 6, looking in thedirection of the arrows;

Fig. 13 is a detail view taken on line 13-13 of Fig. 6.

A brief description of the cabinet embodying my invention will first begiven in order that the adaptability of the interlock and disablingmechanism which permit the opening of the inspection doors at a timewhen the switch is closed, or the closing of the switch while thesedoors are open. will be under stood with greater facility. It is to beunder stood that my invention is adaptable to various kinds of cabinets,whether in this or nonanalogous arts and I therefore do not intend l tolimit myself solely to a cabinet having a switch and fuse unit carriedtherein.

Referring more particularly to Figs. 2 and 5 a cabinet 1 is provided onthe rear wall thereof with a unit base construction for carrying thecontacts of a switch unit 2. and the terminals of fuses connected to theswitch. This unit base construction has been more fully disclosed in acopending application of Albert J. Ball, Serial No. 623,856, filed March7, 1923, and I therefore deem it unnecessary to explain in greaterdetail the construction of this mounting other than stating that units4', capable of individual displacement, carry the various live parts ofthe circuit, and that the units 4 are held in position by a grid 4secured to the back wall of the cabinet by screws 8. The upper units 4carry a plurality of service line terminals 5 and 6. which receive theservice leads, not shown, in any suitable manner from the exterior ofthe cabinet. Co-operating terminal clips 7 are provided adjacent to theservice terminals 5 and 6 on the upper units 4. for receiving the freeend of switch blades 8. At the other end, the switch blades arepivotally carried by a second pair of terminal clips 8i', suitably vmounted upon a second set of units 4 disposed substantially midway onthe grid 4. The switch, which I have shown, is of the quick break typeso that a sudden break will take place between the terminal clips 7 andblades 8 to preventarcing and burning of the contacting surfaces. Aswitch handle 9 is suitably-journaled in the sides of the cabinet and isprovided with an exterior operating handle 10 lying at one side of thecabinet. A pair of fuse terminal clips 11 is electrically connected tothe switch terminal clips 8 on the middle units 4. Directly. below theseterminal clips 11 is a second pair yof fuse terminal clips 12 disposedon a third set of units 4 at the lower end of the cabinet. Any suitabletype of fuse may be employed in the present Construction. However, Ihave illustrated fuses 13 of the cartridge type adapted to bridgeterminal clips 11 and 12.

When the doors are opened, the interior of the cabinet constitutes asingle compartment. In order to separate the switch from the fuse whenit is desired to open certain of the doors while the circuit isclosed,`and as will be explained later, to prevent the removal of thefuses, I have provided a pair of fuse barriers 15 for lying across theterminal clips 11 and 12. These barriers comprise arms 16, extendingfrom the inside face of a fuse displacement door 17, and having crossbars 18 of suitable insulation. Each cross bar 418 lies directly againstone of the air offuse terminal clips when the door 17 1s closed, so thatfuses 13 are locked in the circuit. It will be apparent that any form ofpartition may be used between the switch and fuses so that displacementaccess to the fuses cannot befhad should the switch door be opened whilethe circuit is closed. Access to the switch `is obtained through a door20 closing over substantially the entire switch compartment. Fusedisplacement door 17 hingedly carries a smaller door 22, which affordslimited inspection of the fuses when opened. A latch 23 is provided onthe interior of the fuse inspection.

door 22 in order 'to permit this door to norf mally remain closed on thefuse displacement door 17. This mechanism comprises -a sliding plate 24,having one side turned outwardly and projecting slightly to form a hook25 for'engaging the inner marginal edge of the opening in door 17Sliding plate 24 is controlled by a button 27 carried on the eX- teriorof the door 22. Button 27 is provided adjacent a knob 28, so that upongripping the knob, one of the fingers may be used to operate the button.

Adjacent the side of the cabinet from which the switch handle 10protrudes, an interlock mechanism 30 is provided on the interior of thecabinet. This interlock mechanism is embodied in a suitable casing 31 toprevent unauthorized release thereof when one orl more lof the doors areopened". In other words, it is impossible to operate the interlockmechanism, except by the proper device, which in the present instance is`a suitable projection carried by each door. 'The casing 31 is providedwith an arcuate slot 32, as shown in Fig. 5, to receive the rod 9 of theswitch mechanism. In passing through the casing 31, rod 9 is adapted tointerconnect with mechanism 30 so that the switch may be operated onlywhen the doors are closed. However, I have made certain provisions inconnection with this interlock to release the switch door 2O and thefuse inspection door 22 when the switch is closed, and also forreleasing the switch when it is locked in open position when these twodoors are open. It is to be understood that .this interlock willJfunction to hold the switch in open position while the fusedisplacement door 17 is open, and, vice versa, to hold the door 17closed when the switch is closed.`

Referring now to Figs. 6 to 10 inclusive, I have shown the interlocklmechanism in the various positions: first, of locking the doors closedwhile the switch is closed, second, of

releasing all the doors when the switch isl open, third, of locking theswitch open while the doors are open, fourth, of permitting certain ofthe doors to open while the switch is closed, and fifth, of releasingthe switch to permit it to close while these doors are open.

The interlock 30 comprises essentially two parts, one for controllingthe inspection doors 20 and 22, and the other for controlling the fusedisplacement door 17. A lock bar 35 having translational movement in thecasing 31 is carried by brackets 36 and 37 secured to the side ofthecabinet. The upper end of this bar is cut at an angle and `passesthrough an opening in a depending eye plate 38 carried by switch door20. When door 20 is closed, plate 38 is adapted to engage a projectingtongue 39 on an interconnecting bar 40. Bar 40 extends downwardly, andat the other end is formed with a similar tongue 41. Tongue 41 isadapted to be engaged by a depending eye plate 42 carried on fuseinspection door 22. Normally, the eye plate 42 is engaged by the lowerend 43 of lock bar 35, this end 43 being in the form of aeU and turnedback upon itself in order to lie in the same direction as the other endof bar 35, as shown in Fig. 13. When the doors 20'and 22 are closed, eyeplates 38 and 42 will engage .the ends of bar 35 in snapped relation, tohold the doors in, closed position. In so doing,

plates 38and 42 engage and depress tongues 39 and 41 against the tensionof springs 45 and 46, thereby forcing the bar 40 slightly outwardly. Itis to be noted that the interconnecting bar 40 is carried in oatingrelation so that it is free to move when the tongues 39 and 41 areengaged and depressed. Bar 40 is carried within the casing 3l by a plate47 guiding the upper end, and by the tongues 39 and 41 passing throughsuitable openings in the brackets 37 and 33 secured to the cabinet wall.Springs and 4G suitably connect at one of their ends to bar 40 and attheir opposite end to plates 36 and 37. li switch lock 48 is suitablypivoted to the adjacent wall of the cabinet, and is provided with anengageable, hook-shaped locking finger 49. il spring 50 interconnectsbar 40 with switch lock 43. ln moving outwardly, bar 40 permits theswitch lock 43 to drop back by gravity, or it may drop back through aprojecting stud anchored in the switch leek and riding on the edge ofbar 40, for guiding the switch lock in its movement according to theposition of this bar. Spring 50 connects bar 40 with switch element 48,however, to prohibit the switch element from lagging in following themovement of the bar, or if the element sticks, to give it positivemovement. l

As will be presently explained, locking linger 49 of switch element 48serves to lock the switch in open position, by lying within the locus ofmovement of a projection carried by the switch. A movable plate 51 issuitably carried 0n the switch rod 9. l shall hereinafter term thisplate 51 a switch operated element in order to distinguish it from theswitch mechanism proper. This switch operated element Serves as aninterconnecting member between the switch mechanism and interlock, andis provided in V shaped form with the legs 53 and 54. The switch in moving from closed to open position, as will be seen in lligures 6 and 7,will move the leg 53 downwardly. An engaging lug 55 is suitably carriedon leg 53. Lug 55 is provided with a right angular projection lying inthe plane of switch lock 48. When the leg 53 moves downwardly, lug 55will move past finger49, provided the interconnecting bar 40 has beenmoved outwardly by the eye plates 38 and 42, engaging the tongues 39 and41, and the linger 49 withdrawn from the path of lug 55, either bygravity or through the assistance of the spring 50. Consequently, theswitch may be operated without hindrance. From this description it willbe noted that the interlock functions to release and allow the switch tomove freely to on or olf positions while the doors 20 and 22 are closed,this being accomplished, as above explained, by switch lock 48 beingdisplaced from the path of the switch projection or lug 55, through theinterconnecting bar 40 moving outwardly by engagement with the eyeplates on the inspection doors 20 and 22.

Lock bar 35 is provided with a pin 57 adapted to be engaged by leg 53 ofthe switch element 51, when the switch is open.

if/ssfrie spring 58 is disposed between bar 35 and wall of the cabinet,said spring being secured at one end to bracket 36 and at the other endto bar 35. Spring 58 functions to hold bar 35 normally in engagementwith eye plates 38 and 42. ln opening the switch, leg 53 will comeagainst pin 57, and if the handle 10 is not moved any farther, thespring 53 will hold bar 35 in engagement with the respective eye platesof switch door 17 and fuse inspectiondoor 22. llhus the spring held bar35 may normally serve as a latch to hold the doors closed and preventaccidental release should it be desired to open the switch and not thedoors. But, in order to release the doors 20 and 22, handle 10 is movedslightly farther, so that pin 57 is moved by the leg 53. This additionalmovement operates against the tension of spring 58, and withdraws bothends of bar 35 from engagement with plates 38 and 42, thereby releasingthe switch door 20 and fuse inspection door 22.

As viewed in Figs. 2 and 4, the handle 10 in reaching its extremedownward movement may engage a plate 50 rigidly secured to the exteriorof the cabinet and provided with one or more perforations therein. Thisplate may serve as a stop for the switch handle l0, and also as a meansfor receiving a suitable padlock should it be desired to lock the switchtemporarily in open position. However, l have found it preferable toembody the stop in the interlock mechanism itself, to prevent the bar 35from moving too far.

This stop is in the form of a pin 61 projecting through both sides ofbar 35 and abutting the side of bracket. 37 through which this barpasses.

lhen the switch inspection door 2O and fuse inspection' door 22 areclosed, either singly or together, eye plates 38 and 42 engage theangularly cut ends of lock bar 35, forcing the bar slightly downwarduntil the ends snap into the eyes in these plates, to hold the doorsclosed. The extending tongues 39 and 41 are forced inwardly until theinterconnecting'bar 40 is moved sufciently to brin or allow switch lock48 to drop backwar ly about its pivot point 65 in ordervfor its finger49 to clear the lug 55. llt is to be noted that engagement of one of thetongues 39 or 41 will not be effective in moving interconnecting bar 40a sufficient distance to withdraw the linger 49 of the switch lock 48.Hence, both inspection doors must be closed before the switch may beclosed.

That part of the interlock which locks the fuse displacement door 17will now be described. As above pointed out, lock bar 35 functions tointerlock the inspection doors 20 and 22. I preferably employ a separatelock bar 70, similar to the bar 35, for interlocking with the fusedisplacement door. However, this is not essential and the individualityof operation between the inspection doors and fuse displacement door maybe' eliminated. This individuality in operation Ais desirable as itpermits the use of disabling bar 70 and a bracket 71 also suitablysecured,`

say to the cabinet wall, supports the upper end. When the fusedisplacement door, 17

is closed, a. spring 72 tends to hold bar 70 raised in its upperposition. A suitable stop, such as screw 73, may be provided on bar 70to limit the upward motion thereof. At a point where the fusedisplacement door 17 interlocks with lock bar 70, namely, the lower endthereof, a spring pressed latch 74 is provided. Latch 74 functions tohold the lock bar retracted while the fuse displacement door 17 is open.The action-of latch 74 is against the action of spring 72, consequentlywhen-an eye plate 75 carried by the fuse displacement doorl engageslatch 74 and releases it from lock bar 70, the lock bar will move toupper position. In so doing, the angularly cut end bf bar 70 will passinto the eye of plate 75, and will hold the fuse displacement doorclosed. In Fig. 8, I have shown the position of latch 74 and lock bar 70when the fuse displacement door is open. It is apparent from thisshowing that the latch 74 `extends a sufficient distance beyond theangularly cut end of bar 70 to be engaged by eye plate 75 when the dooris swung closed. Eye plate 75 willflip the latch 74 from engagement witha cross member 76, or other suitable extension, on the lower end of thelock bar 70. f

The upper end of lock bar 70 is provided witha pin v77, which is adaptedto be engaged by leg 53V of switch element 51 when the l switch isopened. As before explained in connection with the releasing of theswitch and fuseinspection doors .20 and 22, the lswitch will be broughtto open position as the leg abuts and moves pin 57. I have provided thepin 77 on lockv bar 70 so that substantially the same action isobtained. If' it is desired to open the fuse displacement#` door 17 whenthe switch is open, continued movement of the exterior switch handle 10is preferably required so that leg 53 of switch element 51 engages thepin 77to move bar 70a sutlicient distance downwardly. It is to be notedthat no other provision has been made for moving bar 70, consequentlythe fuse displacement door 17 can be opened only when the switch isopen.

In Fig.l 7, I have shown the position of the various' parts of theinterlock when the switcli'is open and all the doors are closed.

" In this position, the angularly cut ends 'of lock bars and 70 serve asa latch for holdi ing the respective doors closed, but in a condition tobe opened if switch handle 10 is given the additional movement requiredto move the lock bars 35 and 70 far enough for these ends to clear theeye plates on the doors.A It is understood that this additional movementis not essential to the essence of my invention, but is merelypreferable as it prohibits the doors from iying open as the handle 10 isbrought downwardly to open the switch. It merely serves to simplify thearrangement as practice has proven that some form of latch mechanismshould be provided, so that it is not necessary to have the doors openevery time the switch is opened.

In Fig. 8, I have shown the various parts of the interlock in theirposition when all of the doors are open. As above pointed out, springsand 46 serve to move the interconnecting bar toward the door openings,so that tongues 39 and 41 `will be extended through brackets 36 and 37 amaximum distance. In moving toward the door openings, interconnectingbar 40 tilts switch lock 48 forwardly about its pivot 65, by engagingpin carried on the switch lock. Thus the finger 49 of the switch lock isthrown in the path of lug 55 carried on switch element 51. In thisposition of the switch, lug 55 is within the re-entrant portion offinger 49. In order Ito prevent the switch from being forced to closedposition by bringing lug 55 against finger 49 and forcing it about itspivot vto permit the lug to clear the finger, switch lock 48 is providedwith an extension 80, which abuts against a lateral projection 81 on'lock bar 35. kAt the extreme lower end of lockbar 35, a lug in the formof a screw 82 is provided for abutment against the under- 49, with theresult that the two members' are interlocked and the linger is held frommovement.

I shall now describe the disabling device for rendering the interlock 30ineffective with respect to the switch inspection door 20 and fuseinspection door 22. Assume thatthe interlock mechanism is in a positionas shown in Fig. 6, that is, the doors are closed andthe switch isclosed.y It may be desirable, when the device is in this condition tovobtain access to the interior of the cabinet for inspecting `the switchin order to ascertain the condition of the switch terminals, or toobtain access to the fuses for inspection purposes only. In order toobviate the necessity of throwing the switch to open position, I haveprovided a disabl'er 90 for releasing the switch and fuse inspectiondoorsing bracket 104,

while the switch remains closed. The disabler comprises a rotatablebarrel 91 suitably lcarried on the side of the cabinet adjacent theinterlock mechanism 30. As viewed in Figs. 3 and 9, a key 92 is adaptedto be inserted in this barrel by passing through a slot 93, partly inthe wall ot the cabinet and partly in the projecting portion of thebarrel. A recess 94 is provided in lock bar 35 and a shoulder 95 therebyformed for receiving a ward 96 of the key 92. Movement of the key in acounterclockwise direction, as viewed in Fig. 3, will bring ward 96against shoulder 95 and move lock bar 35 against the tension ot spring58. The lock bar is thereby withdrawn from engagement with eye plates 38and 42 carried by the switch and fuse inspection doors, respectively.Thus these doors are released and may be snapped open to permit thedesired inspection of either the switch or fuses, as shown in Fig. 9.

As soon as the doors are thrown open, the eye plates of course disengagefrom tongues 39 and 41 and allow interconnecting bar 40 to moveforwardly, and as a result bring iinger 49 forwardly to lie in the pathof lug 55. If the switch s ould now be thrown open, lug will engage theupper portion and depress finger 49 out of its path. Finger 49 is freeto move about the pivot as the lug 55 depresses the same by forcing theinterconnecting bar 40 slightly outward by means of pin 60. As soon aslug 55 has cleared finger 49, the latter will again be brought forwardby means of the springs 45 and 46. Thus the interlock is placed 1n acondition to permit release of the fuse displacement door 17, but onlyby continued movement of the switch handle 10. Lock bar will moveagainst the tension of spring 72, through the engagement of leg 53 withpin 77.

However, if it is not desired to open the fuse displacement door -17 butto close the switch'again while the switch inspection door 20 and fuseinspection door 22 are open, the interlock may be rendered ineffectiveby l means of a second disabler 98, which I shall now describe.

InlFigs. 3 and 10, I have shown the switch cabinet with the switch andfuse inspection doors 20 and 22 open, and the switch closed. Thisparticular condition has been ei'ected by means of disabler 98 after theswitch doors were opened by throwing the switch to off position, asshown in Fig. 4. Disabler 98 comprises a movable barrel 99, suitablycarried within the cabinet and protruding slightly from one sidethereof.l A key 100 may be inserted in the protruding portion of thebarrel when the slot therein registers with a slot- 101 cut inthe wallot the cabinet. .Wards 102 of key 100 are adapted to engage a pivotalarm 103. Arm 163 is carried upon a projectreferably mounted on lock bar70. In disabling the switch, the arm 103 is thrown forwardly to engage aprojection 105 on the switch lock 48. Continued movement of arm 103,which results from further movement of key 100, will swing the switchlock about its pivot 65 so as to disable the tin-V ger 49 from the pathof lug 55. As shown in Fig. 10, the switch may then be moved to closedposition with the switch and fuse inspection doors open.

' It is to be noted that the function of disabler 98 is to trip theswitch lock 48 out of locking position with the switch. That is, theswitch lock. is moved sufficiently about its axis to permit the switchto havey free movement, either in being brought to closed position or toopen position. l

Vith switch lock 48 held in this position by disabler 98, it isimpossible to open the fuse displacement door, even though the switchmay be open. If the fuse displacement door were permitted to open atthis time, it is readily apparent that the switch could then be closedagain and the fuses exposed to displacement access while the circuit isclosed. This is prevented by arm 103 holding projection 105 against anythrust that may be imposed thereagainst by arm 53 engaging pin 57 on thelock bar 35, and the lock bar in turn bringing the lateral projection 81against the member 80 of the switch lock 48. Only intended release ofarm 103 from en gagement with projection 105 will restore switch lock 48to a condition where it will again normally function. After the key 100is withdrawn from the disabler 98, arm 103 is returned to its formerpbsition by means of a suitable spring 107.

Keys 92 and 100 may be identical or they may be different, so that aninspector of one class may inspect the switch and fuses and reporttheir' condition to an inspector of another class. Thus repairing theswitch and fuses may be entrusted to a more capable man in order toreduce accidents, usually due to lnegligence of a careless inspector.

Padlocks 112 may be provided to lock the switch door 20 and fusedisplacement door 17 permanently closed. These padlocks engage in.openings in hasps 114 suitably secured within the cabinet 1,

It is, of course, to be understood that I do not contemplate, in everyinstance, the use of two disabling mechanisms, or three doors asarranged herein. Theinterior of cabinet 1 in the present embodiment iscontinuous from end to end when al1 the doors are open, a strap .1x10being provided midway merely to increase the rigidity of the cabinet andto serve as a support along one edge forA the doors 17 and 20 whenclosed. It is apparent that two permanently divided .compartments arepossible in connection with the present dlsclosure, but certainadvantages liein this open arrangement, one of which may be mentioned asbeing the ease with which it is possible to obtain access to the switchand fuse units, when it is desired to remove or repair the same.

I especially wish to emphasize that it is within the scope of theinvention to extend the locking function of the mechanism 30 to lockvarious electrical attachments which it is possible to associate with aswitch cabinet.

I do not intend to limit myself to the details disclosed and described,particularly with reference to the manner of assembling and arrangingthe various parts, as it is quite obvious that it is possible to obtaina combined switch and fuse cabinet having interlocking doors, as iscontemplated within the scope of the present invention, by variousarrangements which may constitute mere equivalency of that which isherein disclosed.

I claim:

l. In combination, a switch, fuses in circuit with said switch, ahousing provided with doors movable to aford access to said switch andsaid fuses, an interlock preventing the opening of said doors while saidswitch is closed and the closing of said switch while said doors areopen, and means for disabling said interlock to permit said switch doorto open while the switch is closed.

2. In combination, a switch, fuses in circuit with said switch, ahousing provided with a door to afford access to said switch and a doorto afford access to said fuses, an interlock for preventing the openingof either door while said switch is closed land the closing of theswitch while said doors are opened, and means for disabling saidinterlock for permitting the switch door to open while the switch isclosed, said interlock having means holding said fuse door in lockedposition upon operation of said disabling means.

3. In combination, a switch and fuses in the switch circuit, a housingprovided with doors movable to aiord access to said switch and saidfuses, an interlock for preventing the opening of said doors while saidswitch is closed, and means for disabling the interlock whereby theswitch door may be opened while the switch is closed.

4. In combination, a switch, fuses in circuit with said switch, ahousing provided with doors movable to afford access to said switch andsaid fuses, an interlock for preventing the opening of said doors whilesaid switch is closed, and means for disabling the interlock to permitaccess to said switch while closed, said interlock associated with saidswitch to prevent access to said fuses while the switch is closed.

5. Incombination, a switch, fuses in circuit with said switch, a housingfor said switch and said fuses, movable doors provided on said casingfor affording access to said switch and said fuses individually, aninterlock for said doors and said switch whereby the doors may not beopened while the switch is closed, said interlock having dis ablingmeans for releasing one of said doors while the switch is closed.

6. In combination, a switch, fuses in circuit with said switch, ahousing for said switch and lsaid fuses, movable doors provided on saidcasing for affording access to said switch and said fuses, an interlockfor said switch and said doors whereby theswitch remains locked in openposition while the doors are open, and means for disabling said switchlock while one of said doors is open.

7. In combination, a switch, fuses in circuit with said switch, ahousing for said switch and said fuses, movable doors provided on saidhousing for affording access to said switch and said fuses, an interlockfor said switch and said doors whereby the switch remains locked in openposition while the doors are open, and means for disabling said switchlock while said switch door is open. v

8. In combination, a switch, fuses in circuit with said switch, ahousing for said switch and said fuses, movable doors provided on saidhousing for affording access to said switch and said fuses, an interlockfor said switch and said doors whereby the switch remains locked in openposition while the doors are open, and means for disabling said switchlock to permit operation of the switch while said switch door is open,said disabling means being inoperative while said fuse door remainsopen.

9. In combination, a switch, a plurality of fuses, a housing` for saidswitch andl said fuses, movable doors provided on said housing foraffording access to said switch and said fuses, an interlock for saidswitch and said doors whereby the switch remains locked in openposit-ion while the doors are open,'

and means for disabling said switch lock to permit operation of theswitch while said switch door is open, said interlock rendering saiddisabling means inoperative as long as said fuse door is open.

10. In combination, a switch, fuses in the circuit therewith, a housingfor saidswitch and said fuses, movable doors provided on said housingfor affording access to said switch and said fuses, an interlock forsaid switch and said doors whereby the switch remains locked in openposition while the doors are open, and disabling means associated withsaid interlock capable of rendering the switch lock ineii'ective uponsaid fuse door being moved to closed position.

11. In combination, a switch and a plurality of fuses, a housing forsaid switch and said fuses, movable doors provided on said housing foraffording access to said `switch and said fuses, an interlock betweensaid switch and said doors lor preventing the closing of the switchuntil the doors have been closed and the opening of the doors until theswitch is opened, disabling means for rendering said interlockineffective to permit opening of the switch door while said switch isclosed whereupon the switch may be opened, and a second disabling meansfor permitting closing of said'switch while said switch door is open.

l2. ln combination, a switch and a plurality of fuses, a housing forsaid switch and said fuses, movable doors provided on said housing foraffording access to said switch and said fuses, an interlock betweensaid switch and said doors for preventinea the closing of the switchuntil the doors nave been closed, a disabling device for said interlockto permit closing of the switch while one of said doors remains open,and a second disabling device for said interlock to permit opening ofsaid door while the switch is closed.

13. ln combination, a switch and a plural-l` ity of fuses in circuittherewith, a housing for said switch and said fuses, movable doorsprovided on said housing for affording access to said switch and saidfuses, means for preventing the opening of either door until the switchis open and the closing of the switch until the doors have been closed,keylike means Yfor rendering said means ineffective to permit access tosaid switch in closed position, and key-like means for permitting theoperation of said switch while the switch door is open.

14. ln combination, a switch, a plurality of fuses, a housing for saidswitch and said fuses, movable doors provided on said housing 'forail'ording access to said-switch and said fuses, an interlock betweensaid switch and said doors for preventing the closing of said switchu'ntil the doors are closed, and key-like means for disabling saidinterlock after said fuse-door is closed but while said switch door isopen to close said switch.

l5. ln combination, a switch, a plurality of fuses, a housing for saidswitch and said fuses, an interlock between said switch and said doorsfor preventing the closing of said switch until the doorsareg closed andthe opening of the doors until the switch is opened, key-like means fordisabling said interlock to permit opening of said switch door whilesaid switch is closed, and a second key-like disabling member for saidinterlock whereby the switch may be closed while the switch door remainsopen.

16. In an electrical cabinet'having a plu-` rality of movable doors, aninterlock for preventing the opening of said doors until the circuit isbroken, disabling means 'for releasing certain of the doors, saiddisabling means being operatwe only when said interlock is engaged byone of said doors,

mesme Lcircuit operating means while the circuit is closed, and meansfor disabling said interlocking means to permit the opening of certainof the doors.

i8. in an electrical cabinet having a plurality of movable doors, meansoperated from the exterior of said cabinet for controlling the openingand closing oi' a circuit within said cabinet, an interlock between saiddoors and said circuit controlling means for preventing movement of thedoors from closed position while the circuit is closed, and means fordisabling said interlock with respect to certain of the doors so thatthey may be opened while thecircuit is closed.

i9. ln an electrical cabinet having a plurality of movable doors, meansfor controlling the opening and closing of a circuit from the exteriorof lsaid cabinet, an interlock between said doors and said circuitcontrolling means for preventing the closing of the circuit until saiddoors are closed, and means for disabling said interlock to permit saidcircuit to be closed while certain of the doors remain open.

20. In an electrical cabinet having a plurality of movable doors, meansfor controlling the opening and closing of a circuit with said cabinet,an interlock between said doors and said circuit controlling means forpreventing the closing of the circuit until the doors are closed and theopening of the doors until the circuit is opened, and means 'lorrendering said interlock ineffective with respect to certain of saiddoors and said circuit controlling means.

2l. ln an electrical cabinet having a plurality of movable doors, means'for controlling the opening and closing of a circuit within saidcabinet, an interlock between said doors and said circuit controllingmeans 'for preventing the closing of the circuit until the doors areclosed and the opening of the doors until the circuit is opened,disabling means for rendering said interlock ineilective to permit theopening of certain of said doors while the circuit is closed, and asecond disabling means for rendering said interlock ine'ectiveto permitthe closing of the circuit while certain of said doors remain open.

22. In an enclosed switch having fuses in circuit therewith, thecombination of doors and switch mechainsm, said doors affording switchand fuse access and fuse inspection, interlocking means associated withsaid switch mecliainsm and cooperating with said doors to preventremoval of said fuses while the switch is closed, and means associatedwith the fuse inspection door to permit inspection of said fuses duringthe time said switch is closed.

switch and fuse access and fuse inspection,

interlocking means associated with said switch mechanism and cooperatingwith said doors to prevent access either to the switch or to the fusesuntil the circuit is broken, and

means associated with 'the fuse inspection door to permit limitedinspection of the fuses durin the time the circuit is closed.

25. n an enclosed switch having fuses mounted within the enclosure, thecombination of interlocking doors including a fuse displacement door andswitch controlled mechanism whereby said fuse displacement door can notbe opened until the circuit is broken, and means for permittinginspection i of saidfuses While said circuit is closed by openin lonedoor.

26. n combination, a switch, a housing thereforfuses within saidhousing, three doors provided on said housing two of which permitinspect-ion of the switch and fuses and the third door displacement ofthe fuses,

'an interlock for normally preventing the opening of the doors until theswitch has been opened, and means for rendering said interlockineffective with respect to said inspection doors.

27. In combination, a switch, a housing therefor having fuses therein,movable doors on said housing for'permitting inspection of said switchland said fuses and displacement l of the latter, an interlock betweenthe switch and said doors for preventing opening of either until theswitch is opened, and disabling means for rendering said interlockineffective with respect to said inspection doors whereby said switchand said fuses may be I inspected while the switch is closed.

28. In combination, a switch, a housing therefor having fuses therein,movable doors on said housin for permitting inspection of said switchand inspection and displacementof said fuses, interlocking mechanism forcircuit therewith, the combination of a said interlock to permit closingof said switch while the inspection doors remain open.

30. In combination, a switch, a housing therefor having fuses therein,movable doors on said housing for permitting inspection of said switch,inspection of said Jfuses and displacement of the latter, an interlockbetween all of said doors and said switch for preventing the closing ofthe switch untilthe doors are closed and the opening of the doors untilthe switch is opened, and disabling devices for rendering said interlockineective to permit independent operation of said inspection doors withrespect to said switch.

31. In combination, a. switch, a housing therefor lhaving fuses therein,said housin having individual doors movable to atfor inspection of saidfuses and said switch and displacement of said fuses, an interlockbetween said doors and said switch for preventing the opening of saiddoors until the switch is opened, and means for releasing saidinspection doors independent of the position of said switch.

32. In an enclosed switch having useslin urality of fuse and switchinspection and use displacement doors, switch operating meansAinterlocking with said doors while said switch is closed, saidinspection doors being interrelated With each other so that they may bereleased from said switch operating means by a single disabling device.

33. In an enclosed switch having fuses in circuit therewith, thecombination of a plurality of movable doors for permitting individualinspection of said switch and said fuses and displacement of the latter,an interlock between said switch and said doors for normally locking thedoors in closed position until the switch is opened, said interlockhaving a separate connection with s aid displacement door to prevent theopening thereof while said switch is closed irrespec- .tive of thecondition of the other doors.

34. In combination, a switch, fuses in circuit with said switch, anenclosure for said switch and said fuses, movable doors on saidenclosure for permitting individual ins ction of said switch and fuses,an inter ook for preventing the opening of said doors while said switchis closed, said interlock including a `lock bar common to both of saiddoors.

35. In combination, an electrical cabinet having a circuit controllingmember therein and fuses in the circuit, doors for'afording access tothe interior of said cabinet and for permitting individual inspection ofthe switch and fuses, and an vinterlock for preventing the opening'ofsaid doors while the circuit is closed, said interlock comprising a lockbar common to said doors and lying parallel therewith when the doors areclosed.

circuit is closed, said interlock having a lock bar common to saidcovers, said lock bar having movement in a plane transverse to the dooropenings.

37. In combination, an electrical cabinet having a circuit controllingmember therein, a plurality of doors on said cabinet movable to affordaccess to t-he interior of the cabinet and for permitting individualinspection ofl the switch and fuses, a lock'bar common to said doorshaving translatory arallel movement to the doors when close andmechanism between said circuit controlling' member and said lock bar forreventing movement of the bar when the circuit is closed.

38. In combination, an electric switch havingfuses associatedtherewith-a casing for said switch and fuses,- doors in said casingadapted'to afford access to the switch and fuses for inspection thereof,a lock bar common to said doors and housed within said casing to preventaccess to said lock bar, and mechanism connected with said lock bar forlocking said switch in open position while said doors are open.

39. In combination, an enclosed switch having fuses associatedtherewith, doors adapted to afford access vto the interior thereof forinspection of said switch and fuses, a lock bar common to said doors forreventing access to said switch and fuses w ile the switch' is closed,said lock bar serving as a latch for temporarily holding said doorsclosed but not locked when said switch is open, and a connection betweensaid switch and said lock bar.

40. In combination, an enclosed switch havin fuses associated therewith,three doors twoo which afford inspection of the switch and fuses and theother displacement access to the fuses, an interlock for preventing theopening of said doors while said switch is closed, said interlock havinga lock bar common to the inspection doors and a lock bar individual tothe fuse displacement door.

41. In combination, an enclosed switch having fuses associatedtherewith, three doors two of which afford inspection of the switch andfuses and the other displacement access to the fuses, a lock'bar commonto said inspection doors for locking the same closed while the switch isclosed, a second lock bar for lockin said displacement access doorclosed whi e the switch is closed, said lock bars being so related tosaid switch that the release of said inspection doors will not affectthe release of said displacement access door if the switch is closed.

42. In combination, an enclosed switch hav- I insane l ing fusesasociated therewith, three doors two of which afford inspection of theswitch and fuses and the other displacement access to the uses, aninterlock between said switch and said doors for preventing the openingof the doors while the switch is closed and the closing of the switchwhile the doors are open, said interlock comprising individual lockingmeans for said inspection doors and said displacement access doorwhereby the inspection doors may be operated independently of thedisplacement access' door.

43. In combination, anfenclosed switch having fuses associatedtherewith, a pair of doors for affording inspection of said switch andfuses and adapted to be locked and released together, a third door foraffording displacement access to said fuses and adapted to be locked andreleased separately, and means between said switch and said doors foreffecting the locking and releasing of the doors.

44. In comination, an enclosed switch having fuses associated therewith,a pair of doors for affording inspection of said switch and fuses, andadapted to be locked and released together, a third door for affordingdisplacement access to said fuses and adapted to be locked and releasedseparately, a lock bar common to said pair of doors and connected tosaid switch through an interlock, and a second lock bar for said thirddoor and also connected to said switch through said interlock, saidinterlock being separately related to said bars.

45. In combination, an enclosed switch having fuses associatedtherewith, a pair of doors for affording inspection of said switch andfuses, a third door for aiiording displacement lof said fuses, aninterlock between said doors and said switch, said interlock including apair of bars, one for the inspection doors and the other for the fusedisplacement door, said bars being movable in substantially parallelplanes.

46. In combination, an enclosed switch having fuses in circuittherewith, a door for inspecting the switch and a door for inspectingthe fuses, a third door for permitting displacement of the fuses, andmechanism for permitting the opening of the inspection doors separatefrom the opening of the displacement door and only' when said switch isopen, said mechanism including a pair of lock bars normally serving asspring operated latches for holding said doors closed.

47. In combination, an enclosed switch having fuses associatedtherewith, a door for inspecting the switch and a door for inspectingthe fuses, a third door associated with the fuse inspection door forpermitting displacement of the fuses, mechanism for releasing theinspection doors from closed position as the switch is opened, saidmechanism also releasing said fuse displacement door when said switch isopen, and means `included in said mechanism for rendering independentreleasing of said inspection doors.

48. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, a displacementdoor for said fuses, an interlock including lock bars for locking thedoors closed, spring means for normally holding said bars in lockingposition, and means on saidv switch for engaging and moving said barsagainst the tension of said spring means for releasing the doors.

49. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, a displacementdoor for said fuses, an interlock for preventing the opening of saiddoors while said switch is closed and the opening of the switch whilethe doors are open, an interlock including parallel lock bars influencedinto engaging position with said doors by spring means, said bars beingengaged for movement against said spring means by said switch as itmoves to open position whereby the doors are free to open.

50. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and said fuses, an interlockbetween said switch and said doors, said interlock provided with commonmeans for locking said doors so that the doors may l not be opened whilethe switch'is closed, and

a disabler for operating said locking means whereby the doors may beopened while the switch is closed.

51.v In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, an interlockbetween said switch and said doors, said interlock including a lock barcommon to said doors'for preventing the opening of the doors while theswitch is closed, said lock bar normally being adapted for movement bythe switch to release said doors, and means independent of the movementof the switch for operating said lock bar.

52. In4 combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses,`an interlockbetween said switch and said doors, said interlock including a commonlock bar normally urged to engaging position with said doors, and aprojection on said switch adapted to engage and move said bar out ofengaging relation with said doors. when the switch is opened.

53. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, an interlockbetween said switch and said doors, said interlock including a commonlock bar normally urged to engaging position with said doors, aprojection on said switch adapted to engage and move said bar out ofengaging relation with said doors when the switch is open, and

key means for engaging and moving said lock bar against its tendency toremain ln-locking position while said switch is closed.

54. In combination, an enclosed switch having fuses associatedtherewith, inspec` tion doors for said switch and fuses, an interlockbetween said switch and said doors for preventing the closing of theswitch while the doors are open, said interlock comprising a lockingmember common to said doors and a switch lock adapted to obstruct themovement of the switch while the doors are open, and an interconnectingbar movable by the closing of said doors for withdrawing said switchlock.

55. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, an interlockbetween said switch and said doors for preventing the closing of theswitch while the doors are open, said interlock comprising a lockingmember common to said doors and a switch lock adapted to obstruct themovement of the switch while the doors are open, an interconnecting barmovable by the closing of said doors for displacing said switch lock,and disabling means for displacin Y said switch lock while the doors areyopen w ereby the switch may be closed. j ,l

56. In combination, an lenclosed switch having fuses associatedtherewith, inspection doors for said switchand fuses, an interlockbetween said switch and said doors for preventing the opening of thedoors while the switch is closed, said interlock comprisinga lockingmember common tov said doors and normally urged to locking position byspring means, a projection on said switch adapted as the switch is movedto open position to -engage and move said bar to release said doors, andmeans lndependent of said projection for moving said locking member.

57. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for said switch and fuses, an interlockbetween'said switch and said doors for preventing the opening of thedoors while the switch is closed, said interlock comprising a memberengaging each door when closed and being normally urged to locking posiytion, a pin on said member, and a projection carried on said switchadapted as the switch is moved to open position to engage said pin -andmove said member '.to releasing position. 58. In combination, anenclosed switch lhaving fuses associated therewith," "inspection doorsfor said switch and fuses, an interlock `between said switch and saiddoors for preventing the opening of the doors while the switch isclosed, said interlock comprising a member engaging each door whenclosed and being normally urged to locking position, a pin on saidmember, a projection carried on said switch adapted as the switch ismoved to open position to engage said pin and move said member toreleasing position, and means operable from the exterior of saidenclosure for directly engaging said member to release said doors.

59. In combination, an `enclosed switch fuses associated therewith,inspection doors for said switch and fuses, an interlock between saidswitch and said doors for preventing the opening of the doors while theswitch is closed andthe closing of the switch while the doors are open,said interlock comprising a common lock bar for said doors and aninterconnecting member engageable by each door as it is closed, a switchlock controlled by said interconnecting member and adapted to lie in thepath of movement of said switch when the doors are open, the movement ofsaid switch to open position releasing saidl doors whereupon the switchlock is projected into the path of movement of the switch as the doorsdisengage said interconnecting member.

60. In combination, an enclosed switch having fuses associatedtherewith, inspection doors for' said switch and fuses, an interlockbetween said switch and said doors for predetermining the movement ofboth the switch and the doors, means included in said interlock forreleasing saidswitch from open position as the doors are closed, saidmeans rendered effective to hold the switch in open position bydisengagement therewith by said doors.

L61. In combination, a switch, an enclosure therefor having a pair ofdoors movable to afford inspection of the interior thereof, means foroperating said switch from the exterior of the enclosure, mechanismbetween said doors and switch operating means for preventing the openingof the doors while the switch is closed, said mechanism having anelement adapted to obstruct the movement of said switch, the position ofsaid element being controlled by the position of said doors, the closingof said doors removing said element asl an obstacle to the movement ofsaid switch.

62. In combination, a switch, an enclosure therefor having a pluralityof doors movable to aord inspection of the interior thereof, means foroperating said switch from the `exterior of the enclosure, mechanism.between said doors and said switch operating means for preventing theclosing of the switch while the doors are open, said mechanism having anelement serving as an obstacle to the closing of said switch, saidelement being removed to allow free movement of said switch as saiddoors are closed.

63'. In combination, a switch, an enclosure therefor having a pluralityof doors movable to afford inspection of the interior thereof, means foroperating said switch from the exterior of the enclosure, mechanismbetween said doors and said switch switch from movement, the engagementof said doors with said spring pressed member releasing said switch lockto permit closing of the switch.

64. In combination, a switch, an enclosure therefor having a pluralityof doors movable to afford individual inspection of two portions of theinterior of the enclosure, means for operating said switch from theexterior of the enclosure, interlocking mechanism between said doors andsaid switch operating means, said mechanism having, a member' movingparallel to the doorl openings and adapted normally to serve as a latchto hold the doors closed while the switch is -open but as a lock toprevent the opening of the doors while the switch is closed.

65. In combination, a switch, an enclosure therefor having a pluralityof doors movable to afford inspection of the interior of the enclosure,means for operating said switch from the exterior of the enclosure,interlocking mechanism between said doors and said switch operatingmeans for prohibiting the closing of the switch until the doors areclosed, said mechanism having a bodily movable member adapted to beengaged by the doors when the latter are closed whereby the switch isreleased and .serving as a barrier to the closing of the switch, saidbarrier member adapted to be liipped out of position for releasing said.switch and permitting it to close.

67. In combination, a switch, an enclosure for said switch having doorsmovable to afford inspection of the interior thereof, means foroperating said switch from the exterior of the enclosure, interlockingmec-hanism between said doors and said switch operating means forprohibiting the closing of the switch until the doors are closed, saidmechanism having a member adapted to be engaged by all of said doorswhen the latter are closed whereby the switch is released and permittedto close. y

68. In combination, a switch, an enclosure,"

spection of the interior of the enclosure,

l means for operating said switch, interlocking' mechanism between saiddoors andV said switch operating means for prohibiting the closing ofthe switch until the doors are closed, said mechanism provided with apivotally mounted barrier ada ted to lie in thepath of the switch, andmeans or flipping said barrier out of the path of the switch as thedoors are closed.

69. In combination, a switch, an enclosure therefor having a pluralityof doors movable to aord inspection of the interior of the enclosure,means for operating said switch from the exterior of the enclosure,interlocking mechanism betweenv ,said doors and said switch operatingmeans for prohibiting the closing of t-he switch until the doors areclosed, said mechanism having a switch lock adapted to hold the switchin open position, the closing movement of said doors releasing saidswitch lock to permit closing of said' switch, and disabling `means forreleasing said switch lock to permit closing of the switch while thedoors remain open.'

- 70. In combination. a switch, an enclosure for said switch havingdoors movable to afford inspection of the `interior of the enclosure,means for operating said switch from the exterior of said enclosure,interlocking mechanism between said doors and said switch operatingmeans for prohibiting the closing of the switch until the doorsv areclosed, a switch lock provided as part of said mechanism for preventingthe movement of the switch., said switch lock being released by theclosing movement of said doors, said closing movement being transmittedthrough another member of said mechanism, and a disabling device fordirectly engaging said switch lock for releasing vsaid switch while thedoors remain open.

71. In combination, a switch, an enclosure therefor having a pluralityof doors movable to aii'ord inspection of the interior of the enclosure,means for operating said switch, interlocking mechanism between saiddoors and said switch operating means for prohibiting the opening of thedoors until ,the switch is open, and means for disabling said mechanismto permit said doors to open while the switch is closed, the opening ofsaid doors, while said mechanism is disabled resetting the interlock toprevent the return of said switch to closed position if then opened.

72. In combination, a switch` an enclosure therefor having a pluralityof doors movable to afford inspection of thel interi or'of theenclosure, means for operating said switch, interlocking mechanismbetween said doors and said switch operating means for prohibiting theopening of the doors while the switch is closed, means for disablingsaid mechanism to permit said doors to open while the switch is closed,the opening of said doors while said mechanism is disabled resetting theinterlock to prevent the return of the switch to closed position if thenopened, and means for releaslng the switch to permit its return again toclosed position while the doors are open.

73. In combination, a switch, an enclosure therefor having a pluralityof doors for aiording inspection of the mterior thereof, an interlockbetween said switch and said doors for `prohibiting the closing of theswitch until the doors are closed and the opening of the doors until theswitch is open, said interlock including a lock bar common to said doorsfor holding the doors closed, said lock bar being inaccessible formanual operation and adapted for movement only by engaging portions ofsaid interlock, said engaglng portions moving said bar as the switch isopened to withdraw the bar from engagement with the doors.

74. In combination, a switch, an enclosure therefor having a pluralityof doors for affording inspection of the interior thereof, an interlockbetween said switch and said doors for prohibiting the closing oftheswitch until the doors areclosed and the opening of the doorsuntilthe switch is closed, said interlock including a common lock barfor locking said doors closed while the interlock is effective and forholding said doors latched but capable of being opened while theinterlock is inetfective, said lock bar being movable out of locking orholding relation with said doors by engaging portions of said interlock,and disabling means for moving said bar out of locking relation withsaid doors while said interlock is effective.

75. In combination, a switch, an enclosure therefor, said enclosureprovided with a pair of doors affording inspection of different parts ofthe interior of the enclosure, means for operating said switch, aninterlock between said switch and doors for preventing the closing ofthe switch until the doors are closed and the opening of the doors untilthe switch4 is opened, said interlock having in` terconnecting meansbetween said doors so that the doors are simultaneously released andlocked, and means included'in said interlock adapted to be engaged bysaid doors upon closing to release said switch from open position.

7 6. In combination, a. switch having fuses associated therewith, anenclosure therefor, doors on said enclosure movable to aii'ordinspection of both said switch and said fuses, a door on said enclosuremovable to afford displacement of said fusesthel area covered by saidfuse displacement door including the area covered by said fuseinspection door.

77. In combination, a switch having fuses associated therewith, anenclosure therefor, doors on said enclosure affording access to twocompartments provided within the enclosure, one of said compartmentscontaining said switch andthe other compartment containing said fuses,the door for said fuse compartment having an opening provided therein, athird door over said opening, and means for preventing displacement ofsaid fuses when said third door is open and the fuse compartment door isclosed.

78. In an enclosed switch having fuses in circuit therewith, acompartment for said switch and a compartment for said fuses, a movabledoor for said switch compartment p and a pair of movable doors for saidfuse compartment, one of said latter doors affording limited access tosaid fuse compartment and the other door affording acces-s to the entirecompartment` and both of said latter doors being operable independentlyof said switch compartment door.

79. In an enclosed switch having fuses in circuit therewith, acompartment for said switch and a compartment for said fuses, a movabledoor for said switch compartment and a pair of movable doors for saidfuse compartm'ent, one of said latter doors affording limited access tosaid fuse compartment and the other door affording access to the entirecompartment, the first of said latter doors being carried by the secondwhereby movement of the second will carry the first therewith, and bothof said latter doors being operable independently of said switchcomparment door.

80. In an enclosed switch having fuses in circuit therewith, two doorssubstantially of the same size for affording access to said switch andfuses, and athird door of smaller size and included within one of saiddoors for affording inspection only of said fuses.

81. In an enclosed switch having fuses in circuit therewith, thecombiation with two doors for affording access to said switch and fuses,of a third door of smaller size and included within one of said doorsfor affording inspection only of said fuses, and means carried by saidfuse access door for preventing the displacement of said fuses when saidthird door is open.

82. In an enclosed switch having fuses in circuit therewith, thecombination with two doors for affording access to said switch andfuses, of a third door included within one of said doors for affordinginspection of said fuses, and insulation barriers carried by said onedoor for lying over and preventing the displacement of said fuses.

83. In an enclosed switch having fuses in circuit therewith, thecombination with a casing having substantially one side thereof coveredentirely by two doors, of a third door carried byone of said doors, andfuse termi nal engaging members on the linner side of said one door forpreventing Athe displacement of said fuse while the door is closed.

84. vIn an enclosed switch having fuses in circuit therewith and anenclosure provided with doors movable to afford access to the interiorthereof, certain of said doors being interlocked with said switch forprohibiting the opening of the same until the switch is open7 another'door being also interlocked with said switch for affording access to theintermediate portions of said fuses but preventing the removal of thefuses, and means for rendering said interlock ineffective to permit saidlast door to open while the switch is closed.

85. In an enclosed switch having fuses in f circuit therewith, thecombination with a casing having two doors provided thereon foraffording access to said switch and fuses, of a third door embodied inthe door for affording access to said fuses, and means for prohibitingthe removal of said fuses while said third door is open.

86. In an enclosed switch having fuses in circuit therewith, thecombination with a casing provided with two doors for affording accessto said switch and fuses, of a third door embodied in the door affordingaccess to said fuses, latch mechanism normally holding said third doorclosed, and'means lying over the terminals of said fuses for prohibitingthe removal of the 'fuses while said third door is open.

87. In an enclosed switch having a casing provided with a door foraffording access to said switch, the combination with a fuse in circuitwith said switch and a second door on said casing for affording accessto the fuse, of a third door associated with said second door forpermitting inspection of said fuse, and means cooperating with saidswitch and Said doors whereby the doors can not be opened until theswitch is open,'said means prohibiting the'releasing of said second doorwithout releasing said third door.

88. In an enclosed switch having a casing provided with a doorfor-affordingaccess to said switch, the combination with a fuse incircuit with said switch and a second door for affording access to saidfuse, of a third door associated withsaid second door for permittinginspection of said fuse, means on said second door forming a partitionwithin said casing between the space carrying said switch and the spacecarrying said fuse, said means serving to prevent the removal of saidfuse while said first or third doors are open.

89. In an enclosed switch having a casing provided with'a door foraffording access to said switch, the combination with a fuse in circuitwith said'switch and asecond door for affording access to the fuse, of athird door carried by and embodiedv in said second door for permittinginspection of said fuse,

`terminals for said fuse, and insulation strips arranged to lie oversaid terminals when said switch is closed to prevent the removal of saidfuse.

90. In combination, a switch having fuses associated-therewith, anenclosure for said switch and fuses, a switch inspection door, a fuse`inspection door, a fuse displacement door, an interlock between saiddoors and said switch for preventing the closing of the switch while thedoors are open, a disabling device for permitting said switch to closewhile said switch inspection and fuse inspection doors are open, saidinterlock rendering said disabling device ineffective while said fusedisplacement door is open. Y

91.v In combination, a switch having fuses associated therewith, anenclosure for said switch and fuses, a switch inspection door, a fuseinspection door, a fuse displacement door, an interlock between saiddoors and said switch for preventing the closing of the*l switch whilethe doors are open, a disabling device for rendering said interlockineiiective to permit said switch to close while said inspection doorsare open, said disabling device being carried on the mechanism of saidinterlock controlling said fuse displacement door whereby said disablingdevice is rendered ineffective while the fuse displacement door is open.

92. In combination, a switch'having fuses associated therewith, anenclosure for said switch and fuses, a switch inspection door, a fuseinspection door, a fuse displacement door, an interlock between saiddoors and said switch for preventing the closing Yof the switch whilethe doors are open, said interlock including a movable bar, said barupon being retracted'adapted to release said fuse displacement door fromlocking relation therewith, and a disabling device for rendering saidinterlock ineffective to permit said switch to close while saidinspection doors are open, said disabling device being mounted on saidbar to move therewith for rendering the device inoperative whilesaidfuse displacement door is released.

93. In combination, a switch having fuses associated therewith, anenclosure for' said switch andfuses, a switch door, a fuse door, aninterlock for prohibiting the closing of said switch while said doorsare open, and a disabling device for rendering said interlockineffective to release said switch and permitl it to close while saidswitch door is open, said disabling device being rendered inoperativewhile said fuse door is open.

94. In combination, a switch having fuses associated therewith, anenclosure for said switch and fuses, a switch door, afuse door, aninterlock for prohibiting the closing of said switch while said doorsare open and the opening of the doors while the switch is closed, adisabling device for releasing said switch door and permitting it toopen, a second disabling device for releasing said switch and permittingit to close while said switch door is open,- said second disablingdevice rendered 'inoperative as soon as said fuse door is opened.

95. In combination, a switch having fuses associated therewith, anenclosure for said switch and fuses, a switch door and a fuse im door,an interlock for prohibiting the closing of said switch while said doorsare open, a movable bar included in said interlock serving to locksaid'fuse door closed, al pivotally mounted arm movable with said bar,said arm adapted to engage a portion of said interlock for rendering theinterlock ineffective and permitting said switch to close while saidswitch door is open.

96. In combination, a switch having vfuses associated therewith, anenclosure for said switch and fuses, switch and fuse inspection doorsmovable on said enclosure, a fusey displacement door movable on saidenclosure, an interlock between said switch and 'said doors forprohibiting the opening of the doors while the switch is closed and theclosing of the switch while the doors are open, said interlockcomprising a plurality of lock bars for locking said doors closed and aswitch lock adapted to obstruct the movement of the switch when in openposition, disabling meansfor releasing said switch lock to permit saidswitch to close while said inspection doors are open, said switch lockwhen released by said means serving to predisplacement door.

97. In an enclosed switch having a casing provided with a. plurality ofdoors for affording displacement access and inspection thereof, thecombination of switch operating means and interlocking means, saidinterlocking means cooperating with said switch operating means and saiddoors, means for rendering said interlocking means ineffective to permitthe closing of said switch while the inspection doors are open, saidinterlock being ineHective to release the displacement access door afterthe switch is again opened.

98. In an enclosed switch having fuses associated therewith, a casinghaving doors afor-ding displacement access and inspection of said switchand fuses, the combination of interlocking means cooperating with saidswitch and doors, said means comprising a switch lock mounted so as tolie in the y.path of the switch while the switch and d'oors are open,and means operable when the displacement access door is closed forrenderin said interlock ineffective whereby said switc may be closed.

99. In combination, a switch and a plurality of fuses associatedtherewith, an enclosure for said switch and fuses, movable doors on saidenclosure, an interlock for preventing said doors to open until saidswitch is open` and said switch Ato close until said doors areclosed,.means for disabling said in- ,vent the movement of one of saidbars and thereby prohibit the opening of said fuseloo

